Tindie

Name: Teensy Adapter for RetroShield
SKU: 18914
Price: 18.00 USD
Availability: InStock
Rating: 4.88 (2 reviews)

Teensy Adapter for RetroShield

(2 Reviews)

Add super powers to your RetroShields

Designed by 8-Bit-Force in United States of America

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Add super powers to your RetroShields

What is it? This board lets you connect your RetroShields to Teensy 3.5 and add super-powers to your 8bit microprocessor :) Uses Teensy 3.5 (sold separately here) much faster (120Mhz ARM vs 16Mhz ...

What is it?

This board lets you connect your RetroShields to Teensy 3.5 and add super-powers to your 8bit microprocessor :)

Uses Teensy 3.5 (sold separately here)
much faster (120Mhz ARM vs 16Mhz ATMega)
more memory (256 KB vs 6K)
micro SDCard connector
Same simple development tools (use existing Arduino IDE programming environment with fast compilation)
8-bit Microprocessors run much faster (6502 and 6809 close to 1.0Mhz clock speeds).

This board also supports NGT30 Video/Keyboard Shield. I like NGT30 because it is possible to make your own stand-alone computer :)

What do you get?

Two options:

PCB w/ SMT parts soldered.
Kit: PCB + connectors

Why did you make it?

Teensy is faster and more capable platform than Arduino, however I had two issues w/ existing Teensy adapter boards:

First was voltage level mismatch. Teensy 3.5 is advertised as 5V-tolerant. What it really means is its inputs are 5V-tolerant. It still outputs 3.3V signals. For most 5V devices, 3.3V is high enough to register logic-high but some microprocessors wanted higher voltages. These did not work reliably or not work at all. Hence I needed true 3.3V <-> 5.0V level shifting.

Second, we read 16bits of address bus and read/write 8bits of data bus to/from the processors. Existing teensy adapters required reading several bit at different gpios and then several bit shift/or/and operations. This wasted precious teensy cycles. I reassigned the Teensy gpio's in groups of 8bit ports to the arduino mega header so reading databus and/or address buses take single cycle teensy instructions. This helps us run the microprocessor fast.

Rates to United States of America

Shipping Rate	Ships From	First item	Additional items
United States Postal Service: Standard Ground Rate Shipping thru US Postal Service. Tracking is usually available. For international shipping, please contact me first - I need to find out about the cost.	US	$4.00	$0.00
United States Postal Service: First Class Package International	US	$13.00	$1.00

Review Breakdown

Average Ratings

Product: (5.00)

Documentation: (4.00)

Shipping: (5.00)

Communication: (5.00)

John | June 15, 2020

Speed up my 6502 Retroshield x 4 times!

I love the Retroshield projects - they are a great way to tinker with 8-bit CPUs and systems. Previously, I was using the Arduino MEGA to host them, but I have now switched to this Teensy kit: I'd never used a Teensy and this was a good excuse to investigate it. Assembly was easy - just the connectors, switches and an LED. Once I programmed it and connected the shield, the CPU ran way faster - I'm estimating about 0.8Mhz which means it's very close to the original Apple 1 speed. Very happy with it!

Alessandro | May 14, 2020

Amazing

Erturk is passionate about his products and wants his Customers to succeed!
I was very excited to find out that 8-bit-Force had already designed what I needed for a 6809-based project.
The design is solid, and the application examples are extremely useful to get me up and running quickly.
In addition to the Retroshield for 6809, I also purchased the Retroshields for 6502 and for the Z80.